Name:DonS
Date:3/5/2010
Build Report:There should be a resistor to 3.3V on the REFP pin, not just a cap. I think this is the positive reference for the A/D converters. The FV-1 data sheet says it only draws 50uA max. The Spin Semi "typical application" shows 100ohm and 1uF on this pin, their development board shows 10ohm and 0.1uF. The dev board values are way too small to filter any 60Hz, so I recommend 100ohm at least.

Name:Dick Thomas
Date:11/11/2009
Build Report:I finally succeeded with this build. The chip works well, but it could use some more control options such as more control of blending the pitch shift with the straight signal.

There are several errors on the layout. This is what I did to finally get the pedal to work. Some of these items have been mentioned in other build reports.

1. The traces are very thin on the layout. I took the transfer into Photoshop and manually beefed them up quite a bit. Any drawing program should allow you to do this.

2. Spinsemi recommends a 15 pf cap from pin 9 to ground by the oscillator. This is not shown in the layout or parts list. I added traces and holes for the cap. I also moved the holes for the crystal oscillator closer together because the leads were very short.

3. The parts list does not list the 15 pf cap, or the necessary crystal oscillator, or IC3 which is a voltage regulator to supply the 3.3 volts to the chip. The layout requires two 100 ohm resistors if you include the LED, but the parts list only calls for one.

4. This is a biggie. The inputs are mislabelled on the layout. The outputs are labelled OK, but the inputs are reversed in relation to the labels on the chip input. I was only trying to use the chip in mono and got NO signal coming through due to the reversed inputs. Once I traced things out with a signal generator I found the error. I switched the input wiring on the jack and all is well.

5. I eliminated IC3 and built a regulated 3.3volt supply on a piece of perf board. I wired it in to the appropriate holes for IC3.

6. The caps just inboard of the input are shown as 0.047 uf on the schematic and 1 nf on the layout. I used the 0.047 and the pedal works.

7. The symbols for the 2N5457 FETs on the layout are not in the correct orientation. Match the actual pinout to the schematic.

8. I used pots off board rather than the trimmers so it would be easier to adjust the controls.

9. Rather than use the three SPST switches I used pots with switches on them (push-pull DPDT using one side) to save space.

10. Smallbear stocks the chip but they did not have the crystal oscillator or cap. I wrote to them and they will be offering these two parts in the future.


Name:5thumbs
Date:9/24/2009
Build Report:I'm preparing to build a similar version of this FV-1 project for a compact amp design I’ve almost completed. Much like those who have posted build reports, I too had to find a suitable 3.3v regulator for my design.

I ended up using the ROHM BA33JC5T ($1.33 USD from Mouser.com, http://www.mouser.com/ProductDetail/ROHM-Semiconductor/BA33JC5T/?qs=4kLU8WoGk0tAiu3UJwCajw%3d%3d).

I'm using a 14.6VDC regulated power supply (think: laptop power supply), so I needed a regulator chip that could handle my input voltage -and- supply the necessary 3.3v and 70mA required by the FV-1. Even if you’re using a much smaller VDC input, this regulator should be able to accommodate your DC input.

Thanks to Francisco for another great FX circuit idea. I had to "roll my own board" due to using a mechanical encoder for the switches, as well as including headers for programming, etc., but I'd have never found the FV-1 without this site. THANKS!!!

Name:Finkster
Date:5/28/2009
Build Report:This is by far the best effects unit to build. The chip is $17 from smallbear, but well worth it. When you add the external eeprom you have up to 16 different effects to choose from. I will be adding a switch and display based on a pic16f628a which will display what effect is currently being used and the pot descriptions for each. The sound is wonderful. Easy to build, but check your fets orientation as I believe the layout has them wrong.

Name:anonymous
Date:3/20/2009
Build Report:At first when I finished my unit it did not work. If you see the data sheet for the fv-1 they recommend a 15pf on x2 (pin 9) and ground. I would recommend it also since the clock i bought did not start without it. Also there was a broken trace on the board I bought from the outl capacitor and the two resistors. After those problems fixed it worked. Would have been nice if the pre programmed programs made better use of the stereo. since most of the effects sounded the same in mono.

Name:Richard
Date:12/12/2008
Build Report:Here is a 3.3V regulator in a TO-92 package (the same package size that most transistors use). It's not listed in the parts section of the pdf for this build, but it is necessary for operation.

LT1121CZ-3.3

http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1003,C1040,C1055,P1368

Max current used by the FV-1 is 70mA. This regulator is rated at 150mA, so no problems with current...

The LT1121 can take up to 30V DC input.

Samples can be found at the Linear site.

Name:Jeffo
Date:7/22/2008
Build Report:Hello.

Check a picture, box's ready.

Works very well! I'm using a 9V ps to power it.

http://img413.imageshack.us/img413/4939/seven4resizezr1.jpg

Name:Doktor Chuckles
Date:5/29/2008
Build Report:For a cheap & easy 3.3v (approx) reg:

You can use a green/yellow LED and an LM317. Use the LED to set a voltage reference at the ADJ pin. This will be approx 2v. The LM317 always has 1.25 volts form the Vout to ADJ pin. This totals 3.25v with is close enough.

More info here http://www.acoustica.org.uk/t/3pin_reg_notes1.html

And get the LM317 datasheet -- the LED replaces R2 on the typical datasheet circuit. Don' t forget the caps and protection diodes.

If you want more info I can get it + a schematic.

Good Luck.

Name:Marko Panic
Date:5/21/2008
Build Report:Not a built report, just a few words of enthusiasm for this project. As soon as I find the way to buy the chip I'll build this 1. It seems very interesting and it sure is challenging.
About the regulator (for Grill)... I think that the LT1083 could do just fine. "Linear" manufactures (and sels) fixed regulators for 3.3V .

http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1003,C1040,C1055,P1278

hope this helps.
Regards,
Marko

Name:Grill
Date:5/19/2008
Build Report: Exelent project, perfect digital deley processor. Surface mouting not so hard.

Name:Jefferson F. Moreira
Date:5/12/2008
Build Report:Building was very straightforward. This project not only provides you
with a nice reverb with that "church/stadium" reverb if you go all the
way on the pots, but also with Flanger+reverb, Chorus+reverb, Tremolo+reverb
and pitch shift, thanks to the FV-1 chip! What a bonus! Unfortunately I am
still stuck before being able to put everything into a box since I could not
find a suitable regulator for 3.3V down here in Brazil. Tried to mess with
the TL431 for doing the regulation but that did not work out as expected.
Tried the circuit with a 2xAA batteries for the chip plus a 9V for the board
and it worked fine.

I tried to contact Francisco about the project but I feel his email
queue is probably very long.

A few issues encountered:

1 - On your middle picture Layout (seen from component side) there are
TWO 1n caps, while in the schematic and also in the parts list you mention
"47n" (0.047uF). Which one should be used? I chose the one on the drawings (1n)

2 - It's missing the Clip LED symbol on the pads at the left middle side
on the layout picture, if that was unintentional.

3 - The 2n5457 (like the J111 I am using - would you recommend it?) is
mounted inverted on the pictures. Check the datasheets to confirm.

4 - The jumper "int-ext" should be connected for the thing to work.
Just a note for the people, like me, who might have any doubts about it.

5 - The switches and trimpots, one can check what effect they do by
downloading the FV-1 datasheet from www.spinsemi.com, or check it here:

Table 1 - ROM Programs

Prg# Description POT0 POT1 POT2
0 Chorus-reverb Reverb mix Chorus rate Chorus mix
1 Flange-reverb Reverb mix Flange rate Flange mix
2 Tremolo-reverb Reverb mix Tremolo rate Tremolo mix
3 Pitch shift Pitch +/-4 semitones
4 Pitch-echo Pitch shift Echo delay Echo mix
5 Test - - -
6 Reverb 1 Reverb time HF filter LF filter
7 Reverb 2 Reverb time HF filter LF filter

Nice fx set, huh?

Well...good luck on the project. If anyone have a clue about the
correct 3.3V reg and could send me a sample or point to a site
who carries it, I would appreciate.

Thanks and happy building!
Jeffo.

http://www.geocities.com/jf_moreira